Italy, Spain and Slovenia expelled a raft of Russian diplomats Tuesday amid increasing outrage over the Ukraine conflict, bringing to almost 200 the number ordered home by EU allies in 48 hours.

After expulsions Monday by Germany and France, Sweden, Denmark and Estonia also followed suit Tuesday -- while the European Union itself declared "persona non grata" a group of Russian officials working with EU institutions.

The expulsions were for alleged spying or "national security reasons", but follow international condemnation of killings in the town of Bucha, near Kyiv, where dozens of bodies were discovered after Russian troops withdrew.

Moscow has rejected Western accusations that its forces were responsible, suggesting the images are fake or the deaths occurred after they pulled out.

Kremlin spokesman Dmitry Peskov told reporters Tuesday that the mass expulsions of its diplomats was "a short-sighted move".

"Narrowing down opportunities for diplomatic communication in such an unprecedentedly difficult crisis environment is a short-sighted move that will further complicate our communication, which is necessary to find a solution," he said.

"And this will inevitably lead to retaliatory steps," he added. 

The expulsions come as the EU discusses a fifth round of sanctions on Russia for its invasion of Ukraine on February 24, with member states expected to sign off on it this week or next.

Unbearable images

Italy announced it was sending home 30 Russian diplomats for reasons of "national security", as part of coordinated action with its EU and US allies.

Later, Prime Minister Mario Draghi called for independent investigations into the killing of civilians in Ukraine that "deeply shake our souls".

"War crimes must be punished. (Russian) President (Vladimir) Putin, the authorities, the Russian army will have to answer for their actions," he said.

Slovenia's government later said 33 Russian diplomats were being expelled and the ambassador summoned to express the country's "shock over the killing of Ukrainian civilians".

Estonia, which shares a border with Russia, said it was expelling 14 Russian consular staff, including seven employees with diplomatic status.

In Madrid, Spanish Foreign Minister Jose Manuel Albares expressed his country's outrage at "the unbearable images we have seen of the massacre of civilians in the town of Bucha".

And the government said it was expelling immediately around 25 Russian diplomats and embassy staff who "represent a threat to the interest of the country".

Keeping dialogue open 

Russia's ambassador to Spain will stay however, to keep dialogue open, "because we do not lose hope that Putin's war will end", Albares said.

Denmark will also keep the Russian ambassador for the same reasons -- while expelling 15 "intelligence officers" accused of spying, the government said.

It condemned what it called "Russia's brutality" in Bucha, saying: "Deliberate attacks against civilians are a war crime."

Sweden's foreign minister, Ann Linde, told reporters it was expelling three Russian diplomats who "conducted illegal intelligence operations in Sweden".

On Monday, France expelled 35 Russian diplomats, German officials said Berlin was sending home 40 and Lithuania expelled the Russian ambassador.

Ukrainian President Volodymyr Zelensky has urged the world to enforce tough new sanctions on Moscow over the killings in Bucha, which he has described as "war crimes" and "genocide".